The present invention relates to combination punch press and laser cutting machines and more particularly to an improved assembly for mounting the laser beam generator on the punch press frame and for delivering the laser beam to the nozzle of the cutting head located on the axis of reciprocation of the ram.
Combination punch press and thermal cutting machines have enjoyed substantial acceptance in providing a high degree of versatility in sheet metal processing since the user may readily punch or nibble small holes and thermally cut larger ones on the container of the finished workpiece. Although plasma cutting had been favored for cost and speed considerations, particularly in some industrial environments, development of improved, relatively low cost high powered lasers has led to wider usage of laser cutting.
Clark et al U.S. Pat. No. Re. 31,042 discloses that it is necessary to space the laser beam generator from the punch press machine in order to isolate it from the punch press vibrations, and also to provide a second work station operation which is offset from the punching station. Klingel U.S. Pat. No. 4,698,480 discloses the advantages to, and an apparatus for, placing the laser beam cutting head at the punching station so that there is a single work station about which the workpiece is moved and suggesting supporting the laser beam generator on the punch press frame. Recently, Amada German Offenlegungsschrift No. DE 3814630 A1 has proposed mounting the laser beam generator on an extension of the base of the punch press machine frame and transporting the laser beam over the head of the frame and then downwardly to the cutting head at a work station offset from the punching station.
Mounting the laser generator on or adjacent the punch press frame does present a problem from the standpoint of minimizing the possible deleterious effect of vibrations on the laser generator. It has been known to use fluid vibration absorbing or damping means under the punch press to minimize the transmission of vibrations to the underlying support for the machine base and then to other equipment in the surrounding environment. The aforementioned Amada Offenlegungsschrift utilizes such fluid absorbing damping means between the machine frame and the laser beam generator. However, both the base and the head of the frame are subject to appreciable vibrations since the base receives the impact of the punching action, and the head reacts to the impact forces delivered to the base by the ram. In C-shaped frames, the head is an elongated element supported only at its rearward end and the punching action is at its forward end so that it may oscillate during the punching operation.
It is also generally considered desirable to produce angular and planar redirection of the laser beam along its path from the generator to the cutting head to avoid polarization of the beam. Moreover, it is desirable to locate the laser beam generator and can transport systems at readily accessible and observable locations.
It is an object of the present invention to provide a novel combination punch press and laser cutting machine in which the laser beam generator is carried on a generally C-shaped punch frame at a location of relative stability and at which the generator is readily accessible and observable.
It is also an object of the invention to provide such a novel combination machine in which the laser beam is transported along the frame to the cutting head in a path which is readily accessible for observation and servicing and which also effects redirection of the beam to avoid its polarization.
Another object is to provide such a machine in which the laser cutting head is readily moved from an inoperative position offset from the punching station to an operative position in which its nozzle is coaxial therewith.
Still another object is to provide such a machine in which various operations are performed rapidly and accurately under computer control.